Pick shafts for looms



3,013,585 PICK SHAFTS FQR LOOMS Lloyd George Urquhart, Westboro, Mass,assignor to H. F. Livermore Corporation, Boston, Mass, :1 corporation ofDeiaware Fiied Oct. 12, 1959, Ser. No. 845,839 Claims. (Cl. 139-147)This invention relates to looms, and in particular to the pick shaftsthereof which transmit motion derived from the loom cam shaft to thepickersticks which pick the shuttle back and forth across the loom.

These pick shafts are subjected to probably the most violent forces ofany parts of the loom, and hence break with annoying frequency, havingan average life of about three weeks in the conventional Crompton andKnowles looms. They are actuated in one direction of their rockingmovement by the impact of the rapidly traveling pick ball against thepick cam bolted on the pick shaft. The force of the blow is delivered tothe cam closely alongside of and at right angles to the pick shaft, andresults in a powerful combined deflecting force and torque exerted onthe pick shaft. Since in these Worsted looms the pick shaft is madeangular in section, in order to fix the pick cam and sweep arm thereonnon-rotatably, this force stresses and fatigues the metal at one cornerof the rectangular section, causing a fracture which speedily spreadsacross the shaft and results in its breakage usually close to theforward end of the rectangular hub of the pick cam on which the blowfalls.

While longer pick shaft life could doubtless be attained by using ashaft of round section, this resort is not practicable because all the,mills using these looms are stocked up with a supply of parts designedto fit only upon pick shafts of rectangular section, which alone areprovided by the loom builder.

These shafts are always made in one piece with a journal of severalinches in length formed on each end and received respectively in a.sleeve bearing forming an integral part of a bracket bolted to theinward surface of the loom side. When the shaft breaks, both brokenhalves of the broken shaft of course have to be removed, together withtheir fittings, namely the pick cam, the sweep arm, and the shuttleejector arm. This can only be done by unbolting and removing one of thebrackets having the pick shaft bearings, because the broken ends of theshaft cannot be otherwise disaligned far enough to slide either of thebroken halves out of its bearing in the bracket. Both of these bracketsare inaccessible until the cloth roll is removed, after which the loomfixer can get at the bracket carrying the bearing adjacent the sweeparm, at the end of the pick shaft nearer the front of the loom, by lyingon his back under the loom, in a position where he is at risk of injuryby the fall of the cloth roll, often heavily loaded, which must be laidon top of the breast beam for lack of any other resting place duringthis operation.

Apart from the cost of the new pick shaft, the job of replacement of theshaft and applyin and adjusting the fittings takes at least /4 of anhour, during which period the loom is of course out of use, a seriouseconomic loss when costly worsted fabrics are being produced.

The present invention aims to provide means for use in existing loomsand usable with the conventional fittings regularly used and on hand inthe mills, which is adapted to save time, effort, cost and hazard ofbodily injury in repairing a broken pick shaft.

To these ends, the invention provides a two-piece or divided pick shaftof which the two component members or halves are joined to rock inunison by a coupling. This coupling, of split sleeve type, is longenough to embrace the two halves throughout the major portion of theinter- 'upon such remainder is withdrawn from its bearing with outinterference. The broken half is then replaced bya new half shaft aftertransfer of the fitting thereto, by

merely sliding its journal into its hearing, all by reaching through theopenings available in the loom side and without disturbing the clothroll.

As will be obvious, the same type of rectangular section pick shaft andfittings is retained, while the coupling bridging the gap between theends serves to transmit the torque, braces the mid-length portion of theshaft assembly against the deflection caused by the pick balls blow, afeature lacking in the prior one-piece shafts, and by the same tokengives more uniform picking by preventing whipping (twisting) of the pickshaft, and saves in the cost of parts because only half of the shaft hasto be replaced, in addition to providing quick, easy and safe repair ofthe damage.

Other objects of the invention, and the manner of their attainment, areas made plain hereinafter.

An illustrative embodiment of the invention is shown in the accompanyingdrawings, in which FIG. 1 is a perspective view of the parts comprisingthe pick motion of the loom, with omission of certain supporting anddriving members.

FIG. 2 is a perspective view on a larger scale showing the noveltwo-part pick shaft with its coupling, but with the pick cam, sweep armand shuttle ejector arm omitted.

The parts of FIG. 1, with the exception of the novel pick shaft 1, arethose of the pick motion of the conventional Crompton and Knowlesworsted loom. It comprises a cam shaft 3 driven in usual manner andcarrying thereon a pick ball or tappet 5 rotatably mounted on the end ofan arm 7 fixed on the cam shaft 3, the pick ball 7 in its orbit aroundthe cam shaft striking the concave I surface of a pick cam 9 fixed bymeans of its rectangular hub and clamping screws 11 on the rear, half 13of divided pick shaft 1. On the forward half 15 of the pick shaft isfixed a sweep arm 17 by means of its hub 19 and clamping screws 21, andalso a shuttle ejector arm 23 with its.

in two halves 13, 15, as noted,'though they are not necessarily of equallength. Each is rectangular in section,

and provided on one end with a journal 33, 35 to be receivedrespectively in the bearings provided as integral parts of the originalbrackets 37, 39, which as usual are bolted to the inward face of theloom frame (not shown). The combined length of the rectangular portionsof the two halves 13, 15, is less than the distance between the hearingsin these brackets by an amount exceeding the length of either journal33, 35, which makes it possible to insert the journal of either half ofthe pick shaft 1 into its proper bearing and then do the same with theother half. without disturbing the fastenings of either bracket 37, 39.That is, the gap provided between the adjacent ends 14 and 16 of the twohalves when in place in the loom permits the axial alignment of the twohalves with each other and with their bearings as needed to enter thejournal of the second half into its bearing, after the first half is inplace. This would be impossible without unbolting one bracket 37, 39, ifthe confronting ends of the two halves overlapped as the second journalis presented to its bearing.

To join the mutually adjacent end portions of the two halves 13, of thepick shaft, a two-part coupling 41 is provided, each part having a rightdihedral internal angle 43 whose sides are of less extent than thewidth. of that face of shaft 1 which they respectively engage, andhaving integral flanges 45 extending in a common plane at both sides ofshaft 1 and equipped with holes 49 through which are put a plurality,herein four, of bolts 47 provided with nuts.

This coupling 41 is made as long in axial extent as possible, for itsbracing effect explained later herein, and for this purpose the forwardhalf 15 of the shaft is made longer, while the rearward half 13, moreprone to break, is made shorter, than its companion piece. Normally thecoupling 41 will match the length of the part 15 measured from the hubof the closest fitting (herein the sweep arm) to its rearward end 16.Thus in installing a replacement for a broken rear half shaft 13 theclamping bolts 47 are merely loosened and the coupling then slid forwardalong the shaft 15 up to such fitting, leaving ample clearance for theforward end 14 of a replacement part 13 in aligning its journal 33 withits bearing in bracket 37 so as to insert it therein.

Once the novel pick shaft is installed, replacement of a broken half isvery quick and simple. It is of course necessary to remove the originalone-piece type of pick shaft following breakage thereof by the familiarand troublesome method of removing the forward bearing bracket 39, sincethe journals in the bearings prevent disalignment and withdrawal of thebroken parts so long as the bearing brackets remain fixed. Thereafter,the forward bracket 39 is bolted in place, the sweep arm and shuttleejector arm are transferred to the forward half 15 of the improveddivided pick shaft, and the journal 35 of this half shaft is inserted inits bearing in bracket 39. With coupling 41 loose on shaft 15 and slidforward to its limit, the rearward half shaft 13 is then equipped withthe pick cam 9 taken from the old shaft and slid into place in itsbearing in rear bracket 37, and the coupling 41 slid rearward so that itembraces equal lengths of the adjacent end portions of half shafts 13and 15, bridging the gap left between them after their journals arethrust home into their respective bearings. Bolts 47 are then tightened,whereupon the pick shaft is in readiness for resuming its work. The slotbetween the opposing flanges 45 of the two portions of the coupling 41permits observation of the position of the shaft ends therein, and guidemarks in the form of notches 51 on the edge of one fiange 45, to bealigned with the respective shaft ends, are provided to indicate thecorrect relative positions of the shaft halves and the coupling.

The coupling 41 which bridges the gap and connects the two halves of theshaft to rock in unison not only transmits the torque from thecam-driven rear half to the front half which actuates the sweep arm, butby its prolonged axial extent serves to brace the shaft against thebending tendency caused by the pick balls blow delivered at right anglesto the shafts axis. Because it further stitfcns the shaft in itsresistance to twisting or whipping, it thus gives more uniform pickingof the shuttle. The novel device further saves in cost of repair parts,since the rear half 13 is nearly always the part that breaks, and itcosts less than one-third that of the full-length one-piece prior shaft.

But the main economy is that noted at the outset herein, that itprovides quick and easy repair of a broken pick shaft, in that onlyone-half of the shaft must be replaced, and therefore only the fittingor fittings on such half need be transferred to the replacement, whichis then put in place, all without the necessity of removing the clothroll and the forward bracket and subsequently returning them to theirplaces. The whole operation is easily performed in 15 minutes as againstabout A of an hour with the prior one-piece shaft. The saving of /3 ofthe time the loom was put out of production in prior practice thuseasily pays the cost of the entire novel structure in a single pickshaft repair when the loom is weaving worsted suitings or similar mediumto high cost fabrics.

A similar economy is attained when a worn or broken pick cam or sweeparm must be replaced, or when as is sometimes required the pick cam mustbe changed to adapt the loom to the weaving of different kinds of goods.

While I have illustrated and described a certain form in which theinvention may be embodied, I am aware that many modifications may bemade therein by any person skilled in the art, without departing fromthe scope of the invention as expressed in the claims. Therefore, I donot wish to be limited to the particular form shown, or to the detailsof construction thereof, but what I do claim is:

1. Picking mechanism for looms comprising in combination hearings infixed spaced relation to each other, a shaft member having an integraljournal on one end mounted in one bearing, a pick cam fixed on suchshaft member, a second shaft member having an integral journal on oneend mounted in the other bearing, a sweep arm fixed on the second shaftmember, and means coupling the two shaft members together to turn inunison and holding them in coaxial relation and spaced apart by adistance as great as the length of a journal on one of the shaftmembers.

2. In combination, a two-piece pick shaft of angular section, a pick camfixed on one such piece, means actuating the pick cam, a sweep arm fixedon the other such piece, means coupling the two pieces together inspaced coaxial relation comprising members each having a dihedral angleengaging two faces of the angular section of each piece, and meansdrawing the members together and clamping them against the said faces ofthe shaft.

3. The combination according to claim 2 in which the axial length of thecoupling means substantially equals the extent of one shaft piece fromthe sweep arm thereon to its end within the coupling means.

4. A pick shaft for looms comprising in combination two shaft members ofangular section each having an integral journal on one of its ends, anda coupling engaging the other end-portions of both shaft members,holding the two shaft members in coaxial relation to each other andagainst relative rotation and spaced apart by a distance as great as thelength of a journal on one of the shaft members.

5. The combination according to claim 4 in which. the coupling isslidable for substantially its length along one shaft member.

References Cited in the file of this patent UNITED STATES PATENTS733,008 Chenu July 7, 1903 1,411,637 Livermore Apr. 4, 1922 2,694,416Dodge Nov. 16, 1954

